DIYstompboxes.com

Does anyone has this schem or knows where to find it?

I'm searching like crazy the schem, layout, project, anything about this Bass Driver DI but I found nothing! Just the GT2...

I think it gonna be awesome for the bassist community to have this project...

A project of other pedal but this same kind of stompbox would be helpful too!

Thanks for reading! Seeya!

Another two tech21 schem
http://www.amtshop.com/index.php?productID=90

Great pedal: I own one and it's a very valuable tool for bass :)
I would be very interested in a schematic just to understand how the effect actually works, but the link provided takes me to a page with some very weird language on it :P

Russian?

Russian, greek or something...

The schem is way bigger than that!

Can someone help us find this rare schem?

This is a pic of someone's PCB of Bass Driver DI: Bass Driver DI PCB (http://k41.pbase.com/o4/69/465269/1/52869876.BASSDI1.jpg)

:o I'm scared, aren't you? What is that black scary thing? OMG!

Guess there is a reason to buy instead of build this pedal ;)
I think I'll open mine as well tomorrow or something, it's really got me wondering what great schematic must be getting all of this done :)

You could also pick up the Behringer clone of it for $40. I haven't tried it, but if you're not afraid of SMD components, you could mod it to your heart's content.

I have used the Sansamp Bass Driver for 10 years, and other than it being a bit hissy, I think it's a great sounding bass preamp/DI.

Roger

Yes, it is russian. Download the RAR archives, extract them and you will see the full schems with PIC switching omitted.

Sorry, didn't see the RAR files.

Very complex huh... Do you know where is the schem for the PIC? I would like to see the digital switching system, I'm so interested in that!

The big black thing in the pic is a piece of foam that's stuck to the board to help hold it in place and keep if from shorting against things inside it's box.
You don't need to know the scheme for the original switching circuit - any logic circuit will do for getting the switching to happen. Personally, I'd rather have it use a system where each channel had it's own footswitch, so you wouldn't have to "scroll" through them with the single button that the original uses.

Constantin,

Thanks very much for the link. The tri-OD is especially interesting to check out.

Was there a link in there somewhere for the Sansamp Bass DI schematic also? I know absolutely NO Russian at all, so I am basically wandering around clicking links at more or less random trying to find things of interest.

I wish American schools did more to teach a broader variety of languages. I got a little French; Russian, Spanish, Japanese and Chinese would have been much more helpful :icon_rolleyes:

I have never actually heard the Sansamp DI, much less played through one, but new schematics are always food for thought.

MR COFFEE, thanks for thanks, but link was posted by Nikolay. I simply pointed out he RARs.
For whatever reason, and I notice it quite often with Russian websites dealing with musical electronics, a lot of stuff is published in *.rar format, so look out for those!
As far as the schematic - unfortunately, thats all these guys have hosted there. I can ask at the russian forums and see if anyone there has it.

.rar is the zip of the underground! All good hacker stuff is in .rar format.

Man, I don't think .rar is underground, its a lot popular.

About the languages. INDEED! I wish I had some Russian class, I know a little bit of English and count 1-10 in German. Spanish I don't bother to learn cuz it's almost the same of Portuguese.

Constantine or Nikolay (or another one who understand Russian) can translate what is on Bottom Left of Tri-OD schem, please? I'm VEEERY interested in these switching systems. Actually, I'm on a project of one of these systems with some friends.

Well, let the big companies to clone it for us... I think its too complex for me right now... someday maybe.

Thanks!

http://home.planetahost.ru/~firewood/teb21.pdf

 :icon_eek: Thanks giego.

Do you know if it's correct?

Thanks a heap for the schematic!  I knew it had a notch filter in there!

I've put together a little summary of the key circuit regions of all the Tech 21 units - see below.  The idea is to provide a way of seeing the differences and commonalities between the units.  From his you can see where each unit stands from the rest.

I've seen a rough frequency response curve for the bass unit and the voicing (notch) filter looks close.  The voicing filters for the guitar and bass are different but I think the bass schem is correct (or at least close to it).

The cab sim part of the circuits vary quite a bit but they seem to be in the same rough ball park.  There is the possibility that the cap values are off by one value due to measurement errors - luja pointed this out some time back on his traces.  Whether the different caps in the cab sim circuits is real or due to measurements is hard to resolve.  Despite this they should sound fairly close.

I"m not sure what to make of the tone control in the Bass Driver - see comment below.

----------------------------------------------------------------------------------------------------
* Stages (Bass/classic Mode)

                   Stage 1   Filter 1              Stage 2       Stage 3
GT2 (lujia/tonepad)   47n/22k    100k/2n2/10n/22n      22n/11k/22k   2u2/2k/23k
GT2 (Dark Angel)     10n/22k        "                  "                    "
Tri-AC               47n/22k    333k/2n2/10n/22n     ~10n/2k5          -
Tri-OD              22n/22k    333k/2n2/22n/22n      3n9/22k         2u2/Rv
Bass Driver DI         n/a           100k/22n              10n/Rv        -

Rv = variable resistance on pot

* Voicing Filter:

GT2          sw   ~22k/9n4/22n/6k2/65k load;  +more filtering
Tri-AC         notch   22k/10n/22n/6k2/40k load;   +more filtering
Tri-OD         notch   22k/4n7/22n/6k2/70k load
Bass Driver DI        notch   22k/22n/47n/6k2/no load


* Cab Sim LPF:
              Stage 1      Stage 2      Stage 3
GT2         28.9k/560p   2n2/1n      -
Tri-AC         22k/470p   2n2/1n      2n2/470p
Tri-OD         22k/820p   2n2/1n      -
Bass Driver DI        28.9k/470p       2n2/1n2      -

* Tone Control:

Same on all but the Tri-AC, which has a mid pot and different bass/treble.
The Bass Driver DI mentioned a different tone control but it's the same as the guitar units!
----------------------------------------------------------------------------------------------------

Looks like the Russian guys have done a through-hole layout:

http://www.hot.ee/wirelessmic/bassdriver.rar

Does anyone know if the layout is actually derived from the jpg, or from another schem?

Hmmm thanks both of u!

What is that "BYPASS - two JFET switches (J112) controlled by discrete flip-flop".

I think something is missing... Don't you?

The original circuit uses some JFET to switch between clean and effect/ampsim.    If you look at the PCB pic posted in this thread you can see a HEF 40xxx (40106?) chip in the top right and to left of the black stuff you can see two JFETS.  That part of the circuit is similar to most commercial effects, and many schems on the net leave that part out. You can replace it with a mechanical switch.  You don't really want true-bypass on this one because it disables the balanced output - see notes below.

I haven't gone over the layout with a fine tooth comb but it definitely looks like it is based on the schematic.

There' a few things to note:
- The XLR circuitry has been removed, everything from R30 and beyond.
- It appears the layout is for a "lite" effects pedal version where the circuit is wired using a bypassing mechanical switch (which bypass the buffers)
- C17 is removed.  Which is part of the bypass/switch stuff.  You can see C20 is hard wired to C21 on the layout.
- The output resistor R28, at the output,  is removed.  It should be put back in.
- There is grayed-out part of the layout - not sure what that is about.  The electro cap appears to be C33.  The other stuff errr..

Regarding the schematic:  The JFET switching has been pulled out a little hastily.    Each of the caps C17, C20 and C21 should have 1MEG resistors wired back to Vb (I traced this from the pcb photo).  The resistors prevent popping when the bypass footswitch is pressed.  (When replacing the JFETs with a mechanical switch, arguably these could also be wired back to 0V.)  This has no bearing on the lite version.

I've perhaps elaborated too much on this so it sounds complicated the above issues are all trivial and easily resolved.

OK I've put together a simplified lite version which performs *identically* to the original but removes the XLR stuff.  Quite a few opamps can be removed.  The lite version is shown with two quad opamps but you could use 4xduals or 2xdual+quad..

http://www.geocities.com/george_giblet/effects/bd21_lite_v10.png

Note: The previous layout given is NOT for this lite version of the circuit.

Thanks George!!

Nice work man! Thanks a lot.

I'll take a better look later.

The original Bass Driver DI has 2 or 3 little black switches, but I can't read what are they. Do you know what are they for?

From what I can see:
- 6.5mm line level or instrument level
- XLR line level or instrument level
- XLR phantom/ground connect; a common thing for XLR.

The first two would probably switch the gain of the appropriate stages.

So... no big deal in not having them?

I'm sorry, but I didn't get the "buffer bypass" thing. Would it be that ON/ON switch? If it is, there is a few parts of the circuit before the bypass, won't it interfer? It can be made with just a SPDT stompswitch ?

Sorry about the obvious questions... I'm quite newbie, and your knowledge is an opportunity to learn... I'm just taking it, if you don't mind, of course.  :D

The line/level switches are nice to have when you need them but you can survive without them. They add to the cost and construction (and are one less thing to go wrong).  No real use for the lite version.

The phantom power/ground lift is an XLR thing.  Not sure how much you know, or want to know, about XLR stuff.   Phantom power is where the thing you connect to supplies power via the audio cable, so you don't need batteries or power supplies at the remote box.  Ground lift is used to help some types of  ground loop problems, which produce humm.   Phantom power and ground lift are completely different things, however, if you lift the ground the phantom power stops working on a lot of equipment.    For an effects pedal both aspects aren't of much use, for the XLR stuff they are part of that world.  You can read up on it:

http://en.wikipedia.org/wiki/XLR_connector
http://en.wikipedia.org/wiki/Balanced_audio

Buffered bypass is where the signal runs through a buffer stage when the effect is bypassed/off (that would be U1:A in my circuit). The advantage of a buffer is the it provides a consistent load impedance to the thing connected to the input, this prevent loss of highs due to long cable runs or when connecting to low impedance inputs (like a sound card or mixer input).   It generally helps keep noise problems down as well.  The other alternative is true-bypass which completely disconnect the effect, so the box is literally wired through.  Neither is better as such but they do have differnt behaviours in different conditions, particularly when multiple effects, long cables, and low impedance loads are concerned.   For bass I think buffered bypass has the edge, for guitar perhaps true-bypass (mainly because some effects need to load the pickup).

The other type of bypass is "output bypass" or partial bypass.  In the this case when the effect is bypassed the effect input circuit is left connected to the input signal and output socket is also wired to the input signal.  With this method the effect adds to the load on the input signal.  If you have a string of effects like this the load can get quite low and affects the tone.  It's not a good method to use but was popular in older effects.  This problem is probably why there was a big movement towards true-bypass mods!

Awesome!

Why are R10 and C10 altered??

Great work George, much appreciated :-)
I own a "real" one so wont be making it but the info is useful, sound guy takes my DI out for the
out front sound and I send the link to my bass rig, sounded great out front and no need for cab mic !

Thanks guys.

> Why are R10 and C10 altered??

To saved an opamp I moved the filter circuit C15, C16, R18, R21  from the output of the filter involving R10/C10 to the input side.  When this is done the two filters interract and the response is changed, *even though no part values are changed*.  To make the filter behave  like the original the R10 and C10 values need to be changed.  The result is a simpler filter which *behaves the same* as the original.  The match between old and new is extraordinarily good, within 0.1dB across most of the band with one point at 0.2dB deviation.  With capacitor tolerance this is closer than the unit to unit variation of originals in production.

Here's a comparison:
http://www.geocities.com/george_giblet/effects/bd21_filter_match.png

I should tell you getting the filter to match was a lot of work (and requires a fair bit of skill).  The fact only two part values changed R10 and C10 makes the task look a lot easier than it was - I was actually surprised how simple it turned out.  Trying to economize filters like this usually requires a lot of part changes to the extent that the filters no longer look remotely similar, even though they behave the same!

You can sleep easy that the unit will behave like the original.

That's excellent work! 8)

Thanks!
~ Charlie

I have a question,

On the original it has a "parallel output". This comes in really handy when playing live (feed it to your amp and run the Bass DI to the house) or even in the studio to have one signal split to the board or to a mic'd amp.
I'm not seeing where they "tapped" it off in the schematic. Is there a buffer stage for it or is it just tapped off the input?

> "parallel output"

By tracing the PCB pics I'm quite certain the parallel out is simply wired to the input terminal ie. no buffering on the parallel out.

Thank you! One more for the road,

If I were to cut out the cab simulator to use with say the ROG "Flipster" as the front end. Where is that located on the schematic? Is the sim in the upper right hand corner (Rx or Cx? to Rx or Cx?)?

I think that the Flipster might be a better front end if you're looking for that "Ampeg" tone. I've always used the Bass DI in the "Ampeg" mode and wished I could separate the cab sim from the pedal to put the Flipster in front.

Perfect! Thank you so much George Giblet.

Now, working on the Layout. Does anyone knows a easy way to do it? I'll try with Multisim's Ultiboard, with no guaranteed success.

I'm just curious...  how is it going to sound with guitar?

a lot of time that I was not exited with a new circuit, I will begin tomorrow!
Thanx George

Rafael

> If I were to cut out the cab simulator to use with say the ROG "Flipster" as the front end.

It's basically the circuit from and including R16 through to and including C14,  you then need to add about 50k from the  C14 to ground.

You probably should remove simple speaker sim (the two RC networks) from the output of the flipset.

I suspect the BD21 speaker sim will load down the Flipster, which will also modify the BD21's cab filter.  Easiest to add a buffer.

I don't really think the speaker sim is has been tuned to match an ampeg, since the basic circuit is the same as other tech 21 products and they clamed to match quite different speakers!

The network R3/C5 through to R5 heavly modifies the response.  On the Tech 21 classic this claimed to produce a Bassman (?) emulation.

>Now, working on the Layout. Does anyone knows a easy way to do it? I'll try with Multisim's Ultiboard, with no guaranteed success.

There's a few free one around PCB express is another.  Most are about the same, it's just a matter of perseverance and familiarity.

Let's work on it.  ;)

How could I add a mid knob to this??? I usually don't like the cut in mids on my bass pedals

The non-existance of a mid controller doesn't mean that the mids are cutted.

I think it can't be so hard, anyway it's a good idea!

George, can you help us with it?

Ps: There is a pedal with mid controller, its the Sansamp Para Driver DI (very similar to Bass Driver)

Check, no mids :) (http://www.geocities.com/george_giblet/effects/bd21_filter_match.png)

To get rid of the mid notch: put the R10 and C10 values back how they were in the original schematic and delete parts C15, C16, R18, R21.  These parts serve to mimic a typical bass amp EQ for the DI in the original.  For a mid control you can use any mid control you like. Place it before or after the bass/treble controls.    The Tech21 TRI-AC shows an example.  Unfortunately for the Bass unit adding the mid control will cause the signal to invert.

While we're talking about this, can we identify what the various tone-shaping portions of the circuit are? Here are the ones I can recognize:

1. One just before the presence control including R3, R14, R15, C5, C6 and C7. This is a LPF yes?

2. The presence control is a freq-dependent gain (top boost?) by virtue of C11

3. One just before / including U2:C, another LPF?

4. The mid-notch George just described above with R18, R21, C15 and C16

5. U2:D has some tone tweaking, possibly in conjunction with #4?

6. U1:C has C22, which would make gain freq-dependent, yes?

7 . U1:D is obviously the TREBLE and BASS controls

Thanks,
-- Don P. --

> One just before the presence control including R3, R14, R15, C5, C6 and C7. This is a LPF yes?

Oh, forgot about that bit.   It's a kind of HPF *BUT* it also has a whoping deep notch!  To get rid of the notch pull R3 (100k).

You could try pulling that instead of, or as well as the R18, R21, C15 and C16 stuff.

[Ed: I might add that the plot I gave with the slight mid-notch  only shows the effect of R18 through C16 (and one of the low-pass filters).]

OH yeah, but that's what I said, you don't need the "mid pot" to have mids.

How do I make the VCC+ and VCC- of the TL074? 9V and GND? Or do I have to use 9V and -9V ?

I don´t see a big improvemet using a +- supply (but you can use two 9V in serie to have more headroom). just connect vcc to 9V and Vcc- to ground , remember VB is VCC/2-

Ok, thanks.

So... No losses using GND as Vcc- ?

Vb it's on the schem, no problem with that. I just need to know about the Vcc- and Vcc+ cuz I'm making the layout.

I´m making a layout too it is 90 routed I just need to put the values and make some order with the names and values.
if you want to wait a couple of days it will be available here.

REALLY??  :icon_biggrin: :icon_biggrin:

Man!!! I will aprecciate that! I was killing myself on the layout!

Thanks!!

so i don't start with my own version for no reason, would that be a perf, etch or vero layout?

I don't like perf or vero. PCB is better!

i prefer vero, but i guess this circuit might compel me to enter the world of etching.

PCB of course, too much parts for vero o perboards .

Just curious...

Do you use Fibergrass boards? How do you etch it? How do you drill it?

I have a question about C33, it is near a specific op amp??? it don´t seems to be bias or supply filter(220uF is enough) maybe is a decoupling cap for a specific op amp in that case 47u is a very high value...

I use standard boards is not easy get fiberglass boards here, I use a laser printer and glossy paper and I have a big drill . my arm is crying out for a little one...   

So, laser print + glossy paper really works huh...

Well.. I don't see any C33, even if I had I would not be able to answer, maybe George would.

the pcb that I´m routing is for the triangular ear schematic using 2 quad op amps and two dual op amps . if you don´t want the balanced output you can save one op amp for other project.

ok here is the pcb , part list and schematic all in one file trying to be like FP :D

http://download.yousendit.com/4A8AEB7F6152F83B
and
plexilandia.googlepages.com


this is an UNTESTED board, if you try it and it have an error please post it here.

enjoy
12afael

thanks a milion, i'm gonna build and test it as soon as possible.

Thanks 12afael!!!

Very nice "chara" !

U will search for TL07*, then I'll build!

Thanks a loooooooot!  ;D

Err... I don't see a real use for the XLR output for me, I know that it's better to have than not to have but... That adds more money for the cause, an IC, some Resistors and Caps, a XLR socket. I'll get an estimate of the project and see if, for me, XLR output would worth it.

If I decide it wouldn't, then I'll make a new PCB layout based on yours, if you let me. OK?

Thanks!

shakal, if you don´t want the balanced output just don´t put the ic4, c26 , c30, c28, r38, r39, r35, r36, r44 and r43.

I think the balanced output is a very good issue to this box, it is usually used to record on recording studios that use balanced inputs. if your bass have a XLR input you can use it and you will have less noise. if you are in a stage without an amp you can use the PA and if you have an amp you can have an extra sound for the mix.

QuoteIf I decide it wouldn't, then I'll make a new PCB layout based on yours, if you let me. OK?

no problem

the PCB is being tested at this moment by a friend. we found that C20 was backward. now it is corrected on pcb vercion 2.0. the pcb is the same.

plexilandia.googlepages.com

new revision drive and treble were backwards too. :icon_redface: just in case you want to wire the pots directly on the board.
we have another issue. when the level and blend are at max the unit don´t pass audio. it´s like a bad biased device, maybe there is a resistor missing on the triangula ear schematic.

Rafael

Common mistakes for first versions... Don't worry, nobody will kill you!   :D

The thing about XLR is that I'm not a professional bass player, yet... But I'll think about it later.

Hey, just curious... Where do you live?

Chile south america.

Hey comprade! Brasil aqui!  ;D

Hey, how it sounded? There is any other issue to solve? Did you found the error about the missing resistor?

it seem to sound good , my friend that test it is from other city . the issue is when he blend is full clean and the vol at max, I`m working on this.

 Someone  build it? Any updates?

To George Giblet:

      On the bdi21_lite schem you wrote abot the HPF formed by the blend pot and C14. Can you explain me a little more this?
      The circuit filters more  the processed signal as we blend more clean signal? Is that correct?

Thanks. :)



By the way, I think i'm going to mix the gt-2 and bassdriver (look SO similar) so I can use the MIC switch.

(http://www.sugardas.lt/~igoramps/article65/article65_clip_image004.jpg)

The OFF AXIS is near identical to the bassdriver. Using th CLASSIC position I can add the mids control that STM posted some time ago.

Image from http://www.sugardas.lt/~igoramps/article65.htm
     

at this moment I only know of two units that use the pcb that I made. both have a issue with the blend control, yesterday I test one of theses units, and it sound fantastic. just I need to buy a 1mm drill to build mine. the owner of this unit say that it sound really different that the gt2.

I must build it to try to fix the blend control. still I don`t know what is happening I suppose that the output is goin to one rail. I have a amek2500eq clone with a similar problem.

Quote from: 12afael on August 31, 2007, 10:35:23 PM
I must build it to try to fix the blend control. still I don`t know what is happening I suppose that the output is goin to one rail. I have a amek2500eq clone with a similar problem.

English version:

Looking to other blenders schematics, wouldn't be necesary to put a capacitor from the clean buffered signal to the lug of the blend pot?

Spanish version:

Así me explico mejor. ;) Es que viendo otros blenders como el paralooper o el de ROG cuando mezclan la señal limpia con la de efecto antes del pote en cada lado hay un condensador. ¿Has probado a insertar uno?

I working right now mounting parts on the pcb, I will do some test to fix the problem.

saludos
12afael

Hey what's on?

Did u make it? How is it?

I only need two caps to make it work. I hope to finish it this weekend.

Wow! I'm glad u made it, compadre!

I'm just waiting you to send the green sign and then I'll build it!

Thanks, see ya!

any updates on this project?

Mine it's working.  :D I'm using the gt2 tonepad pcb beacuse they are very similar."Just" needs to add and extra board to get the blending part.

(http://i226.photobucket.com/albums/dd99/goaltoday/Bass/BDDI.jpg)

Now it's time to mod!!!  ;D

can you make some test around the blend pot?
I regret to say that I have not had time to find a cure for the problem of the blend, at this moment a friend is testing the pedal so I do not have it here to test it.

I suspect a resistor between the first op amp output to the blend pot could make the trick.

my last board have a little issue on SW3. I want to update it with a final solution to the blend problem.

Quote from: 12afael on November 15, 2007, 09:33:57 PM
can you make some test around the blend pot?

- No problem with the blend pot but I've got some ic voltage values I don't like.

- Following your pcb would be  pins 5&6 from IC1 that vary from 3.8-5 if I change the drive pot.  :o

- The rest of the voltages look OK.

So when you get your sansamp back please measure those voltage to compare. Thanks!.

mmm I will try to check that. it must be a issue with the load because the drive pot is one stage after the ic1b.
feedback should make the input impedance bigger , if it is changing too much could be part of the problem.

I will try to check it.

- I've measured those values on my behringer clone of the bassdriver and has similar values. So I supose that's the way it is.  ???

- It sounds  good and that's what matters,no?  :D

- Before trying a proper mids control I'm going to replace the 100k and 22k that controls the two mid-notchs. I don't want to end with 8 pots, too much to drill... :icon_mrgreen:

any chance of have pictures of the guts of the behringer clone?

It includes true bypass, mids control and a new blend control.

Ugly Inside:  ;D
http://img510.imageshack.us/img510/7160/dscf0378ek5.jpg

Outside:
http://img258.imageshack.us/img258/3705/dscf0377vj3.jpg

If you want more inside pictures just tell me.

Was this project ever verified? I'm getting all the parts for it, but I want to make sure its going to work before I start.

Thanks!

Quote from: O on January 09, 2008, 09:47:48 PM
Was this project ever verified?

- The schem is correct, except maybe  a capacitor between the clean-buffered signal and the lug of the blend pot. It works without that capacitor.

- You can use the PCB that posted 12afael, that I believe it's been verified.

- Or you can adapt the sansamp GT-2 board as I did. Just need an extra board to include the blend function. I'll ask F.Peña permission to publish the modified board and schem.

Later I'll post some clip.  ;)

Thanks Kornell, I would appreciate it.

Quick and short clip: http://boomp3.com/m/b387fec9406e

Clock settings: Presence: 1:00 Drive: from 1:00 to 5:00 Blend 5:00 Bass&Treble 11:00

Mine is not the stock version because I feel it lacks some mids and has too much bass.
If you search on  the www there's lots of  clips using the original version.

Cool clip!

I think I know what I'll be building this weekend :D

I build it, seems to sound good but have a question about the volume. Looking with an oscilloscope with drive = 0 and level=10 the output signal is like the input signal in amplitude (no amplification) is that correct?

When I add drive the volume increase. Regards

Is build this weeks ago using the schematic traced by DIZ(rectangular ear bass 21). 5 dual opamps except the DI circuit. I'm not sure if the schematic is correct though but anyway this schematic has a punch after all!!I mean after building it and tested it

Quote from: DimebuGG on February 15, 2008, 05:46:41 AM
Is build this weeks ago using the schematic traced by DIZ(rectangular ear bass 21). 5 dual opamps except the DI circuit. I'm not sure if the schematic is correct though but anyway this schematic has a punch after all!!I mean after building it and tested it

Any pics? :D

It's just the GT-2 PCB and then modified. the 5th op amp is offboard.

I'll try to post pics.

to anyone who wants to build 12afael's layout:

Lift off  R47 and R48...."+" side of C20 faces R25 and remove the other 2.2uF cap(C21) then put a jumper on it.

Remove C17( connected to CW of BLEND pot) also and install a jumper.

Quote from: DimebuGG on February 18, 2008, 12:32:46 PM
to anyone who wants to build 12afael's layout:

Lift off  R47 and R48...."+" side of C20 faces R25 and remove the other 2.2uF cap(C21) then put a jumper on it.

Remove C17( connected to CW of BLEND pot) also and install a jumper.

Does this fix the "blend cutting off" issue?

Sould I use linear or log for pots? Sorry for the stupid question...noob to the DIY world

Quote from: 9re9 on March 18, 2008, 12:53:22 PM
Sould I use linear or log for pots? Sorry for the stupid question...noob to the DIY world

Just use linear ones but if it doesn't suffice your taste then use audio tapered. Anyway i'm using 100K linear pots.

hi, has anyone made a new layout and parts layout similar to a project pdf for this without the xlr outputs? i dloaded the one by 12afael but it was a bit confusing, and i dont really need the xlr output
i would really appreciate it if there was, hehe
you can send it to awi_ball@yahoo.com or post it here, whatever's easier, thx alot guys, and more power :icon_mrgreen:

guys im about to build this but i got confused with the schematic so i just want to clarify some things.  so the sw1,sw2,sw3 is the bypass(on/off) switch right? so its not true bypass? then the xlr, is it phantom powered or not? also the 3 small black switches in the original sansamp isnt included in the build? thank you very much

Most of the links are dead here, can anybody refresh them?

Try plugging them in here, you'll probably get some to work.

http://www.archive.org/

hello my name is Radek - i have some question about schematic bass driver tech21 DI . Is schematic tringular ear bass driver di the same what original schematic ??? I created clone of bass driver di - it has got big noise at max high pot. I would like to compare original schematic with this that i have got - if someone has got original schematic, can send it to me? my mail bulabla@o2.pl thx & cya